The investigations of tribo mechanical properties of coatings obtained with electrocontact welding of sintered powder materials and powderpolymer fillers of Russian manufacture are presented. It is proved that the introduction of antifriction components (powders of copper or tin) into filler material at a rate of 5-10 % increases the time to joints seizure by 1.5-2 and decreases by 1.5 the friction ratio. The application of powderpolymer and sintered fillers reinforced with metal grid produces a relief on the operating surface of the coating with the areas possessing minimum hardness. They are worn out more intensely and the forming herewith grooves help to keep lubricating oil on the friction surface. For the friction pair operating in abrasive wear conditions with adhesive wear elements, at welding it is recommended to use powder compositions (by weight): 80-90 % -PG-FBX6-2, 10-20 % of copper powder friction ratio

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In agar production one of the most common technological operations is cutting of soil or plants. It makes up at least 70% of the total volume of mechanized works. The purpose of this study is to help maintain the agrotechnological parameters of the cultivator's blade by coating the blade with powder wear-resistant coatings using the one-sided gas-flame surfacing technology. The technology of strengthening the cultivator blade using one-sided gas-flame surfacing is applied. As a result, were defined: powder granulation on the thickness of the applied layer; modes and parameters of the one-sided gas-flame surfacing during the formation of composite material coating. Foreign experience of the last decades shows that with the development of gasometric spraying methods it is possible to atomize various materials such as polymers, carbides, metals. These coatings withstand the impact of high thermal loads, shock-abrasive and chemically active environments. Comparison of application methods mentioned above shows that the quality of coatings expressed in the parameters: adhesions, porosity, oxidation levels remain at approximately the same level. However, a comparative analysis of foreign practice has shown that the method of gas-flame surfacing is more technological, more productivity, and the specific costs of the coating are reduced.

There are a number of difficulties in the electrical contact welding of powder materials: shedding of powder from the surface of a cylindrical part, impossibility of hardening the layer during welding due to flushing of the powders with coolant and unstable flow of powder into the welding zone. One solution is pre-spraying the powder in some way. (Research purpose). The research purpose is investigating the possibility of electric contact welding of metal powders preliminarily sprayed by a gas-flame method, namely, adhesion strength and losses during preliminary gas-flame spraying of powders. (Materials and methods) Powders of grades PG-NA-01, PrKhIIG4SR, PRZh3.200.28 were sprayed onto flat samples of St3 steel, polished to a roughness of Ra 1.25. The strength of powder adhesion to the base was studied by the cut method. (Results and discussion) The percentage loss of the powder as a whole is 3-23 percent for all the distances studied. The greatest powder losses appear at a distance of more than 180 millimeter from the tip of the burner for powders of grades PG-NA-01 and PrKhIIG4SR. The smallest powder losses were observed for PrZh3.200.28 powder, which totaled 3-7 percent. The maximum adhesion strength of the sprayed powders to the surface was 22.1 megapascals' when spraying the PG-NA-01 powder. The adhesion strength of powders of the grades PrKhIIG4SR and PrZh3.200.28 is small and amounts to 0.2-3 megapascals'. (Conclusions) The use of preliminary flame spraying of powders for their further electric contact welding is possible using PG-NA-01 grade powder, while the best adhesion to the base (that is more than 20 megapascals') is achieved with a spraying distance of 120-140 millimeter. The smallest powder losses during flame spraying are achieved at a spraying distance of 100-160 centimeters', at which the powder loss for the studied grades was 4-12 percent.